Logarithmic approximants: Difference between revisions

Wikispaces>genewardsmith
**Imported revision 542276828 - Original comment: **
Wikispaces>genewardsmith
**Imported revision 542277300 - Original comment: **
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<h2>IMPORTED REVISION FROM WIKISPACES</h2>
<h2>IMPORTED REVISION FROM WIKISPACES</h2>
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: This revision was by author [[User:genewardsmith|genewardsmith]] and made on <tt>2015-02-26 12:59:53 UTC</tt>.<br>
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: The original revision id was <tt>542276828</tt>.<br>
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which is about 1.4 semitones short of three octaves.
which is about 1.4 semitones short of three octaves.


The logarithmic size of an interval with a given frequency ratio can be conveniently notated as that ratio underlined. Thus __3/2__ is the perfect fifth. This can also be expressed by an explicit function: if bim(q) = (q-1)/(q+1), then __q__ = bim(q). The inverse function can be written mib(q) = (1+q)/(1-q).
The logarithmic size of an interval with a given frequency ratio can be conveniently notated as that ratio underlined. Thus __3/2__ is the perfect fifth. This can also be expressed by an explicit function: if bim(r) = (r-1)/(r+1), then __r__ = bim(r). The inverse function can be written mib(v) = (1+v)/(1-v).


Three types of approximants are described here:
Three types of approximants are described here:
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which is about 1.4 semitones short of three octaves.&lt;br /&gt;
which is about 1.4 semitones short of three octaves.&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
The logarithmic size of an interval with a given frequency ratio can be conveniently notated as that ratio underlined. Thus &lt;u&gt;3/2&lt;/u&gt; is the perfect fifth. This can also be expressed by an explicit function: if bim(q) = (q-1)/(q+1), then &lt;u&gt;q&lt;/u&gt; = bim(q). The inverse function can be written mib(q) = (1+q)/(1-q).&lt;br /&gt;
The logarithmic size of an interval with a given frequency ratio can be conveniently notated as that ratio underlined. Thus &lt;u&gt;3/2&lt;/u&gt; is the perfect fifth. This can also be expressed by an explicit function: if bim(r) = (r-1)/(r+1), then &lt;u&gt;r&lt;/u&gt; = bim(r). The inverse function can be written mib(v) = (1+v)/(1-v).&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
Three types of approximants are described here:&lt;br /&gt;
Three types of approximants are described here:&lt;br /&gt;